"Matt O'Toole" wrote in message
news
On Fri, 12 May 2006 10:30:00 -0700, Capt. JG wrote:

Back to more questions somewhat related to the Perkins 4-108. This
sailboat
is a pig to back up. It really wants to prop walk to starboard. According
to
the owner, it's got a fixed, 3-blade prop. I believe the boat also has a
folding prop aboard in a locker. Would that help? Would tuning help? What
do
you think?

Prop walk is caused by the design of the boat, mostly the downward angle
of the prop shaft. The more downward angle, the worse the walk will be.
Other factors contribute too, but that's the main one.

Changing the prop may cause a noticeable difference, but not enough to
matter.

Folding props reverse poorly, and won't help. Feathering props, such as
Max-prop's, actually reverse better than fixed props. This won't stop the
walk but it will give you more control.

On some boats I just put the wheel hard over and pulse the throttle, or
goose the tranny in and out of gear. The alternate turning forces cancel
each other, and with luck (and no wind) the boat goes straight back.

Practice!

Matt O.

FWIW, I have a Catalina 30 and have had both a fixed 2 blade and a fixed 3
blade prop on it. The prop walk is definitely and noticeably worse with the
3 blade. The diameter of both props is the same. Others on the Catalina 30
list claim that when they switched from the standard-issue 2 blade fixed
prop that usually comes from the factory to a Martec folder that the prop
walk goes down.

--Alan Gomes